1.a person who is so skillful(mainly at fighting/shooters games) it looks cheesey, but sadly they can become cheesey at any moment.
2.a person who can beat you using either their skill or by being cheesey

EX. Guy 1:"The guy was so good, every time he threw a grenade. dude missed on purpose just to shoot me down then later fucking fragged me to death"
Guy 2:" you got your ass whoop by a Masta Cheese, lol"